i got 22k rank in jee main. what is the best college i could get in cse

Congratulations for your result. You know the cutoffs vary every year and you haven't mentioned details like your category or home state you belong to. It might be difficult to get top branches such as Computer Science and Engineering in top NITs as the closing rank of those NITs lies around 8000. However, you can expect computer Science and Engineering in NITs like Raipur, Patna, Hamirpur, Sikkim, North East NITs under all India Quota as you haven't mentioned your home state. Coming to IIITs, you have a good chance of getting Computer Science and Engineering in IIITDM Kurnool, IIIT Trichy, IIIt Kottayam, IIIT Dharwad, IIIT Kalyani etc. However this is based on previous few years' data and this year the cutoffs may change. You can check the cutoffs here http://engineering.careers360.com/articles/nits-cutoff-for-top-btech-branches
http://engineering.careers360.com/articles/jee-main-cutoff-for-top-iiits
I would suggest you to use the Jee Main college Predictor tool to know about your admission possibilities http://engineering.careers360.com/jee-main-college-predictor?icn=QnA&ici=qna_answer